Electron Configuration of Phosphorus (P)

What is the electron configuration of Phosphorus?

The electron configuration of Phosphorus (P, Z=15) is 1s² 2s² 2p⁶ 3s² 3p³. In noble gas shorthand: [Ne] 3s² 3p³. It has 3 unpaired electron(s) and is a p-block element.

SymbolP
Atomic Number15
Full Electron Configuration1s² 2s² 2p⁶ 3s² 3p³
Noble Gas Shorthand[Ne] 3s² 3p³
Blockp
Period3
Group15
Unpaired Electrons3
Exception?No

Orbital Filling Order

Following the aufbau principle, the 15 electrons in Phosphorus fill orbitals in order of increasing energy: 1s (2 electrons), then 2s (2 electrons), then 2p (6 electrons), then 3s (2 electrons), then 3p (3 electrons).

Each orbital is filled according to the Pauli exclusion principle (at most 2 electrons per orbital) and Hund's rule (electrons occupy degenerate orbitals singly before pairing).

Noble Gas Shorthand

The inner electrons of Phosphorus match the configuration of Ne. This allows us to abbreviate the configuration as [Ne] 3s² 3p³, where [Ne] represents the filled core and the remaining entries show the valence electrons.

Valence Electrons

The valence shell of Phosphorus contains 2 electrons in the 3s subshell and 3 electrons in the 3p subshell. These outermost electrons determine Phosphorus's chemical reactivity, bonding behavior, and position in the periodic table as a p-block element in period 3.

Visualize orbital filling with 3D orbital shapes, aufbau principle, and noble gas shorthand for 36 elements.

Explore Phosphorus in the Electron Configuration Explorer

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